Machine for cooling metal sheets or plates

ABSTRACT

The machine for cooling metal sheets or plates comprises a casing having at least two parallel planar portions in facing relation to each other and defining therebetween a gap whose width exceeds the thickness of the sheet to be cooled so as to define two chambers with the sheet. A series of sheet guide and support rollers extend transversely of the longitudinal direction of the sheet. The casing comprises part-cylindrical portions surrounding the rollers and the planar portions are disposed between two adjacent ones of the rollers which are located on the same side of the sheet. Cooling water is supplied to the chambers and flows in a direction substantially parallel to the plane of the sheet.

United States Patent [191 Dalian et al.

[4 1 May 27, 1975 1 MACHINE FOR COOLING METAL SHEETS OR PLATES [75] Inventors: Gilbert Mordekha'llhouda Dahan,

Villepreux; Jean Schrempp, Jouy-en-Josas; Stephane Georges Jean-Marie Viannay, Plaisir, all of France [73] Assignee: Usinor, Paris, France [22] Filed: Apr. 19, 1974 [21] Appl. No.: 462,580

Gutterman 134/122 X 12/1964 Grimes 134/64 X 2/1968 Hayunga 134/64 X [57] ABSTRACT The machine for cooling metal sheets or plates comprises a casing having at least two parallel planar portions in facing relation to each other and defining therebetween a gap whose width exceeds the thickness of the sheet to be cooled so as to define two chambers with the sheet. A series of sheet guide and support rollers extend transversely of the longitudinal direction of the sheet. The casing comprises part-cylindrical portions surrounding the rollers and the planar portions are disposed between two adjacent ones of the rollers which are located on the same side of the sheet. Cooling water is supplied to the chambers and flows in a direction substantially parallel to the plane of the sheet.

12 Claims, 8 Drawing Figures a a I "A R \\\\\\\\\\\\\\\\\\\I:

PATENTEUHAYZYIBYS 3,885,581

SHEET 2 MACHINE FOR COOLING METAL SHEETS OR PLATES The present invention relates to processes employed for cooling metal sheets or plates and to the machines and plants for carrying out said processes.

At the present time there are two main processes for cooling metal sheets issuing from rolling mills. The first comprises plunging the sheet in a bath of stagnant water. However, this results in only limited heat exchanges bearing in mind the low speed of displacement of the sheet and the resulting limited-renewal of the cooling water. This process therefore does not permit the obtainment of sufficiently high cooling rates when it is applied to relatively thick sheets or plates. In a second process, a cooling liquid, for instance water, is spraid onto the surfaces of the sheet, but this process also has serious drawbacks. First it is clear that the cooling of the sheet occurs in an uneven manner, since the water spraid onto the lowersurface rapidly falls in the form of a shower whereas the water spraid onto the upper surface is discharged with difficulty and accumulates at a depth which may be as much as several tens of centimetres. Under these conditions, the renewal of the water occurs at a relatively low rate so that the cooling is limited. In an attempt to accelerate this renewal, it has been found necessary to increase considerably the force of the sprays directed onto the sheet and this considerably increases the power required for pumping and the cost of the plant. Moreover, the recovery and discharge of the enormous masses of water employed present serious problems.

An object of the present invention is therefore to provide a machine for cooling sheets which overcomes the aforementioned drawbacks of conventional machines and enables in particular high cooling rates to be attained for the treatment of thick sheets or plates without however increasing to an excessive extent the power employed.

The invention provides a machine for cooling sheets or plates comprising sheet support and guide means, a casing having at least two parallel planar walls disposed in facing relation and defining therebetween a gap whose width exceeds the thickness of the sheet to be cooled so as to define two chambers with the sheet, and means for circulating in said chambers a current of cooling water which moves in a direction substantially parallel to the plane of the sheet, wherein the machine comprises a series of parallel guide rollers which are disposed transversely of the longitudinal direction of the sheet, said casing including planar walls disposed between two adjacent rollers which are located on the same side of the sheet, and substantially cylindrical portions surrounding said rollers.

In view of the fact that sheet guide means are provided to preclude deformation of the sheet, water is made to flow around said guide means. The water may be supplied in the region of some of these rollers whereas it may be discharged in the region of other rollers.

It will be understood that this machine may be embodied in various ways or with various configurations corresponding to the various aforementioned manners of carrying out the process. These various embodiments will now be described with reference to the accompanying drawings which are given solely by way of example and in which:

FIG. 1 is a partial diagrammatic view of a machine according to the invention;

FIGS. 2 to 6 are similar views of modifications of the machine;

FIG. 7 is a partial perspective view of a partial modification of the machine, and

FIG. 8 is a diagram of a cooling plant according to the invention. I

FIG. 1 shows a part ofa machine according to the invention for cooling metal sheets or plates, as the metal sheet T, the mean thickness of which may be as much as, or even exceed, 30 mm. This machine comprises a series of support and guide rollers 10a, 10b; 11a, 11b. Broadly, the essentialelements of the machine, disposed symmetrically onv each side of the mean plane of the sheet, will be designated by the same reference numerals to which index a is added for the upper elements and b for the lower elements. The machine comprises a metal casing or enclosure 12 which extends between the guide rollers at 13a, 13b and surrounds the rollers at 14a. The planar walls 13a, 1312 are substantially parallel to each other and define a gap exceeding the thickness of the sheetso as to define with the latter two chambers 15a, 15b having a width 2. Water circulating means comprise at least one supply pipe 16a, 16b extending for example throughout the length of the rollers 10a, 10b and at least one discharge pipe 17a, 17b also extending throughout the length of the rollers 1 1a, 11b.

As shown in FIG. 8, in which the reference numeral generally designates the machine described briefly hereinbefore, a cooling plant may comprise a cold water tank 120 at room temperature or at 20 to 25C which supplies water to the machine 100 through a pump 101 or under the effect of gravity, a hot water tank 103 to which the water is conducted as it leaves the machine, a heat exchanger 104 which is supplied with primary cooling water by a pump 105 and with water coming from the tank 103 by a pump 106. This exchanger supplies the tank 102 with water cooled by the primary fluid.

The operation of the machine according to the invention will be described with reference to FIG. 1, it being understood that, broadly, this description also applies to the other illustrated embodiments of the machine.

The cold water supplied to the machine by way of pipes, such as 16a, 16b, and discharged by way of pipes, such as 17a, 17b, flows in the chambers 16a, 16b in a direction parallel to the longitudinal direction S of the sheet, that is to say, in the same direction as the direction of translation of the sheet, or in the opposite direction. The speed of movement of the water current or flow is in any case higher than the speed of translation of the sheet.

Without it being necessary to explain the process of the heat exchange between the sheet and the cooling liquid, it will be easily understood that the forced circulation of a sheet of water having a thickness of between a few millimetres and a few centimetres on each side of the metal sheet results in a sufficient cooling of the latter. Moreover, this cooling is perfectly homogeneous in the directions of the width and length of the sheet and on each side of the latter. Further, as the enclosure or casing 12 is closed, the flow of the water outside the machine is limited to a few inevitable leakages which are therefore in no case comparable to the torrential flows which occur when a sheet spraying process is employed.

It will also be easily understood that the power required for pumping the mass of cooling water alongside the .sheet is substantially less than when high-power spray jets are required for passing through the mass of water which accumulates above the sheet in the conventional process.

The fact of providing rollers inside the machine surrounded by the cooling device permits the construction of a machine whose length may be equal to that of the longest sheets to be treated while the machine allows a correct treatment of smaller sheets.

Further, the fact of providing a plurality of places in which the cooling liquid is supplied and discharged, the cooling or quenching liquid results in a higher flow, and consequently a substantially higher rate of treatment than in prior processes, it being possible to arrange that this rate of treatment in particular corresponds to the rate of displacement of the sheet through the rolling mill.

Theembodiment shown in FIG. 2 differs from that of FIG. 1 in the provision between two sets of rollers a, 20b; 21a, 21b in the region of which the water is respectively supplied and discharged at 26a, 26b; 27a, 27b of at least one set of additional rollers 29a, 2912 which are also surrounded by the casing 22. This shows that various solutions may be envisaged as concerns the arrangement of these rollers and the supply and discharge pipes. The operation of the machine shown in FIG. 2 is similar to that described hereinbefore.

In the embodiment shown in FIG. 3, the water is supplied and discharged by way of pipes 36a, 36b; 37a, 37b which communicate with chambers 35a, 35b in regions at equal distances from the two sets of adjacent rollers 30a, 30b; 31a, 31b or 31a, 31b; 32a, 32b. The means for supplying and discharging the water of course extend transversely throughout the width of the sheet T. The operation of the machine is, here again, similar, although in this embodiment the water has to flow around rollers such as 30a, 30b; 31a, 31b; 32a, 3212 which might present a few particular problems which may be, for example, solved by the improvement shown in FIG. 4. Note that this improvement is also applicable to the other embodiments described.

In order to avoid the formation of water wedges or corners in the vicinity of the guide rollers 40a, 40b, there are provided deflectors 41 which extend from the portion 42 of the casing the nearest to this zone form ing a curvilinear dihedral, roughly along the bisector plane" of this dihedral. According to another feature, these deflectors are orientable so as to facilitate, for example, the introduction of the sheet T or modify the conditions under which the water circulates.

It is also possible to envisage, as shown in FIG. 5, the construction of a casing 52 which is substantially continuous and extends around rollers 50a, 50b through which rollers the water supply and discharge is effected. For this purpose, the rollers are hollow (see bores 53a, 53b) and include radial passages 54a, 54b which open onto their periphery. As in the embodi ments shown in FIGS. 1 and 2, sets of adjacent guide rollers, or sets of guide rollers separated by other sets of guide rollers, serve respectively to supply and discharge water. However, this embodiment, which is of interest from the point of view of homogeneity of the cooling, has the drawback of embossing or goffing the sheets since the guide rollers are not smooth.

When a machine according to the invention is placed in a production line, certain stages or parts of the processes may have to be modified and in particular the cooling may have to be eliminated. It is then desirable that the machine be capable of being traversed without damage by the sheets brought to high temperatures. Thus, as shown in FIG. 6, there may be provided in the guide rollers a, 60b; 61a, 61b and in the casing 62 appropriate cooling means. Here, the rollers are hollow and are traversed, for example, by a stream of water 63, whereas the casing 62 has a jacket 64 through which water 65 or other cooling fluid also flows.

Machines have been hereinbefore envisaged in which the water travels in a direction parallel to the direction F of translation of the sheet. It is also possible in accordance with the invention to arrange that the water flow in a direction transversely of the direction of translation of the sheet. This modification is shown diagrammatically in FIG. 7 representing guide rollers a, 70b; 71a, 71b on each side of the sheet T and a casing 72 surrounding the rollers and the sheet. In the part of the casing located between two adjacent sets of rollers there are provided, on each side of the sheet, two supply pipes, such as 72a, which extend in the longitudinal median plane of the sheet throughout the lcngtl; between the two adjacent sets of rollers. In this embodiment, the water moves transversely of the direction F and may be collected by suitable means alongside the longitudinal edges of the machine,

In accordance with the same principle, it could also be envisaged to supply the chambers 75a, 75b from one of the longitudinal edges of the sheet and to collect this water alongside the opposite longitudinal edge.

The machine according to the invention may be employed in two different ways:

a. In static operation: the sheet is fed into the machine empty of water, the liquid is supplied and circu lates with respect to the stationary sheet which is then removed from the machine.

b. In dynamic operation: the sheet passes through the machine without stopping which enables the overall length of the machine to be reduced. If this operation is carried out in accordance with one of the embodiments shown in FIGS. 1 to 6, homogeneity in the mechanical characteristics of the sheet is achieved at all points. This arrangement is therefore preferred.

It must be understood that other modifications may be made in this machine without departing from the scope of the invention. In particular, in order to render the machine capable of receiving sheets of different thicknesses or to regulate the performances, the casing may be constructed in two substantially symmetrical parts adapted to be displaced vertically with respect to each other so as to adjust the gap between the facing horizontal walls. The adjusting means employed may then be for example similar to those employed for adjusting the gap or nip between the rolls of the rolling mill producing the sheet. The machine may also be made adjustable in width. The means for affording lateral fluidtightness or sealing must of course be adapted to allow such adjustments and the water circuit must also be adjustable correspondingly.

Further, the form of the orifices through which the water is supplied or discharged may be chosen to suit the various arrangements. For example, these orifices may be continuous or discontinuous.

Having now described our invention what We claim as new and desire to secure by Letters Patent is l. A machine for cooling metal sheets or plates, comprising a casing having at least two substantially planar and substantially parallel portions in facing relation to each other and defining therebetween a gap having a width which exceeds the thickness of the sheet to be cooled so as to define two chambers with the sheet, means for supplying said chambers with a current of cooling water which moves substantially in a direction substantially parallel to the plane of the sheet, a series of parallel sheet support and guide rollers which are disposed transversely of the longitudinal direction of the sheet, said substantially planar portions being disposed between two adjacent rollers of said rollers which are located on the same side of the sheet, the casing further comprising substantially part-cylindrical portions surrounding said rollers.

2. A machine as claimed in claim 1, wherein the water is supplied and discharged in at least some of said part-cylindrical portions.

3. A machine as claimed in claim 1, wherein the water is supplied and discharged in at least some of regions of the casing which are located between two sets of rollers.

4. A machine as claimed in claim 1, wherein the rollers are hollow and include radial passages which put the interior of the rollers in communication with the periphery of the rollers and through which passages the water is supplied and discharged.

5. A machine as claimed in claim ll, comprising deflectors in the vicinity of regions of connection between the planar portions and the part-cylindrical portions of the casing, said deflectors extending from said connection regions toward a sheet-receiving gap between ad jacent and corresponding rollers.

6. A machine as claimed in claim 5, wherein the deflectors are adjustable in position.

7. A machine as claimed in claim 1, wherein the gap defined between the planar portions of the casing is adjustable in width.

8. A machine as claimed in claim 1, wherein the guide rollers are hollow for receiving a flow of cooling fluid therethrough.

9. A machine as claimed in claim 1, wherein the casing is metallic and includes a jacket in at least its planar portions for receiving a supply of cooling fluid.

10. A machine as claimed in claim 1, adapted to receive sheets of different widths, the water supply means being correspondingly adjustable.

11. A machine as claimed in claim 1, wherein the means for supplying the water are located in the vicinity of a longitudinal median plane of the sheet and means for discharging the water are located alongside the edges of the sheet.

12. A machine as claimed in claim 1, wherein the means for supplying the water are located alongside each one of the edges of the sheet. 

1. A machine for cooling metal sheets or plates, comprising a casing having at least two substantially planar and substantially parallel portions in facing relation to each other and defining therebetween a gap having a width which exceeds the thickness of the sheet to be cooled so as to define two chambers with the sheet, means for supplying said chambers with a current of cooling water which moves substantially in a direction substantially parallel to the plane of the sheet, a series of parallel sheet support and guide rollers which are disposed transversely of the longitudinal direction of the sheet, said substantially planar portions being disposed between two adjacent rollers of said rollers which are located on the same side of the sheet, the casing further comprising substantially partcylindrical portions surrounding said rollers.
 2. A machine as claimed in claim 1, wherein the water is supplied and discharged in at least some of said part-cylindrical portions.
 3. A machine as claimed in claim 1, wherein the water is supplied and discharged in at least some of regions of the casing which are located between two sets of rollers.
 4. A machine as claimed in claim 1, wherein the rollers are hollow and include radial passages which put the interior of the rollers in communication with the periphery of the rollers and through which passages the water is supplied and discharged.
 5. A machine as claimed in claim 1, comprising deflectors in the vicinity of regions of connection between the planar portions and the part-cylindrical portions of the casing, said deflectors extending from said connection regions toward a sheet-receiving gap between adjacent and corresponding rollers.
 6. A machine as claimed in claim 5, wherein the deflectors are adjustable in position.
 7. A machine as claimed in claim 1, wherein the gap defined between the planar portions of the casing is adjustable in width.
 8. A machine as claimed in claim 1, wherein the guide rollers are hollow for receiving a flow of cooling fluid therethrough.
 9. A machine as claimed in claim 1, wherein the casing is metallic and includes a jacket in at least its planar portions for receiving a supply of cooling fluid.
 10. A machine as claimed in claim 1, adapted to receive sheets of different widths, the water supply means being correspondingly adjustable.
 11. A machine as claimed in claim 1, wherein the means for supplying the water are located in the vicinity of a longitudinal median plane of the sheet and means for discharging the water are located alongside the edges of the sheet.
 12. A machine as claimed in claim 1, wherein the means for supplying the water are located alongside each one of the edges of the sheet. 